20 13 Anhui senior high school entrance examination mathematics
They speak very carefully-and ~ ~ accurately-if you don't understand, just figure out what an independent event is and how to arrange P and combination C, and then you will suddenly understand-you will really appreciate the fun of being an expert in understanding cows in the future-encourage you! ! -In the college entrance examination, you must always find innovation and learn to have an epiphany.-You will see cheerful fireworks set off in this space at any time ~ ~ * *